ICP 9MPD050F12B1 Installation Instructions Manual page 43

HONEYWELL SV9541M "SMART VALVE" Sequence of Operation
I POWERAPPLIEDTO APPUANCE
l
I
THERMOSTAT CALLS FOR HEAT
¢
I PRESSURESWITCHESPROVED OPEN?
i
I COMBUSTIONBLOWER ENERGIZED
I
PRESSURESWITCHESCLOSEDWITHIN 30 SEC-
ONDS?
3 SECONDPRE-PURGE
PILOT VALVE OPENS:
IGNITORPOWERED(1)
PILOT LIGHTSAND FLAMEIS SENSED I_uI
DURING90 SECONDTRAILFOR
IGNITION?
_I YES
MAIN VALVE OPENS,
HEATING FAN "ON" DELAY BEGINS
AFTERDELAY:CIRCULATINGBLOWER STARTS I
I
FLAME SENSE LOST?
THERMOSTAT CALL FOR HEAT ENDS
_ NO
I P,LOT AND MAIN VALVE CLOSE I
COMBUSTIONBLOWER DE- ENERGIZEDAFTER 30
SECONDPOST PURGE
ICIRCHLAT_NG BLOWER OFF AFTER DELAY I
/ WA. FOR NEXT CALL FOR HEAT I
L l
I
WAITFOR PRESSURESWITCHESTO OPEN
_1_ COMBUSTIONBLOWERDE- ENERGIZED
_[ FIVE MINUTEWAIT PERIOD
I
L THREE SECOND FLAME FAILURE RECYCLE DELAY
PILOT VALVE CLOSES;
PILOT IGNITOROFF
YES
.[ PILOT AND MAIN VALVECLOSE
FLAME SENSE LOST MORE THAN FIVE I
TIMES INTHISCALL FOR HEAT?
J--
NO
YES
J
I CIRCULATINGBLOWER OFF AFTER DELAY I
+
COMBUSTIONAIR BLOWER OFF AFTERPOST
PURGE
(1) Ignitor "ON" for first 30 seconds of trial for ignition,then "OFF" for next 30 seconds. If the pilot has
not lit, it turns back"ON" for the final 30seconds. The pilot valve remains energizedduring the entire
90 second trial for ignition.
NOTE: If main limit string opensandtakes longerthan 2 minutesto close, system goes intoI hour wait
period.
440O1102004 [_